Page:Popular Science Monthly Volume 92.djvu/216

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��Popular Science Monthly

���A new sound -producing device. These hollowed cups cleverly imitate the clatter of a horse's hoofs

��Ashes From Burned Wood Make a Good Fertilizei

DO not bewail the fact that the price of commercial fertilizers has gone beyond the reach of all except the wealthy- farmer. It is because potassi- um oxide, one of the important ingredients of a good fertilizer, has jumped from four hundred to eight hundred dollars a ton. But any farmer can proc^uce his own potassium oxide from the fresh ash of burned twigs, branches and other parts of such hardwood trees as the beech, birch and maple. It is a very simple process requiring a cheap apparatus and no complex chemical treatment. The College of Forestry at Syracuse will give information to anyone about the process.

��Ripsaw tee^h

��How the Cavalcade Approaches Behind the Scenes

EVERY barnstorming com- pany has as not the least important part of its equipment a pair of hollowed cocoanut shells, which in the hands of the stage mechanic, sound more like a horse than a horse itself. Now that most of our melodrama comes to us through the motion pictures, along comes an imita- tor of clattering hoofs to be attached to a stationary organ. It is operated from the keyboard by a lever or button. With the aid of a swell box, the sound can be made to swell or diminish.

The device consists of six cups, the upper three of which are secured to the bellows and the lower three of which are mounted on a solid base. To operate them, the organ player presses a key which causes the first cup to come down with a thud, followed in quick succes- sion by the other two cups. There is no break in the action. The cups are made of maple. The inventor is Harold A. Val- kenburg, of Oakland, C'alifornia.

���Tlie toothed sides trim away enough wood to keep the blade from binding

��New Key Hole Saw Which Will Not Jam or Bind

ANEW saw has been invent- ed by A. R. Brewer, of Northport, Washington. It not only has teeth along one edge, as has an ordinary blade, but the sides and upper surface are toothed also. Made in this way, the saw can cut itself out of any predicament. The toothed sides automatically trim away enough wood to keep the blade from binding as it goes down into the cut. These same toothed sides may be used as a rasp to widen out laterally the hole that is being made.

The saw is designed for both rip and cross-cut work. The pointed end of the blade is chan- neled out much like a reamer, so that by giving it a twisting motion, it is quite able to bore its own way into the wood in starting a hole. The chisel-like handle provided at the other end, facilitates this action because the blade may be driven into the wood with a mallet if the twisting motion at the start does not prove sufficient.

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